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Proposed Rule

Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This proposal would require an inspection of the fuel tube assembly of the auxiliary power unit (APU) for clearance from adjacent components; and inspecting the fuel tube assembly and the bleed air duct shroud for discrepancies (insufficient clearance, nicks, dents, chafing, or other damage); and related investigative and corrective actions if necessary. This proposal also would require relocating certain support clamps on the APU fuel tube assembly. This action is necessary to prevent a fuel leak caused by chafing of the APU fuel tube assembly, which could result in fire in the center wing area. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 18, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-285-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-285-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York.

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FOR FURTHER INFORMATION CONTACT:

Sarbhpreet Singh Sawhney, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; telephone (516) 228-7340; fax (516) 794-5531.

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SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-285-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-285-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on certain Bombardier Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 airplanes. TCCA advises that an investigation of a fuel leak revealed chafing of the fuel tube assembly for the auxiliary power unit (APU). This fuel tube assembly is on the bleed air duct shroud, which is located in the center wing area where it is attached to a fairlead by two support clamps. It is possible that incorrect location of these support clamps may result in insufficient clearance between the fuel line and the bleed air duct, and/or between the fuel line and the gust lock cable. If there is insufficient clearance, the APU feed tube assembly can chafe, which could result in a fuel leak and possible fire in the center wing area.

Explanation of Relevant Service Information

Bombardier has issued Service Bulletin 8-49-19, Revision A, dated July 7, 2003, which describes procedures for doing a visual inspection of the APU fuel tube assembly. This inspection includes examining the routing of the fuel tube assembly to ensure that the tube has sufficient clearance between the shroud of the bleed air duct and the gust lock cable; and inspecting the fuel tube assembly and the bleed air duct shroud for other discrepancies such as nicks, dents, chafing, or other damage. If the visual inspection shows no discrepancies, the service bulletin specifies to relocate the clamps on the APU fuel tube assembly. If the visual inspection shows discrepancies, the service bulletin describes procedures for related investigative and corrective actions before relocating the support clamps for the fuel tube assembly. These related investigative and corrective actions include: Start Printed Page 28864

  • Blending out the damaged area and measuring the depth of the reworked area.
  • For fuel tubes on which damage (nicks, chafing, or dents) is within acceptable limits: Doing an eddy current or fluorescent penetrant inspection for cracks. If cracks are found, or if the damage is outside the acceptable limits specified in the service bulletin: Reworking/repairing the tube assembly or replacing it with a new or serviceable tube assembly.
  • Visually inspecting the replaced tube assembly for fuel leakage after rework or repair.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. TCCA classified this service bulletin as mandatory and issued Canadian airworthiness directive CF-2003-22, dated September 3, 2003, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models are manufactured in Canada and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, TCCA has kept the FAA informed of the situation described above. We have examined the findings of TCCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact

We estimate that up to 125 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $8,125, or $65 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2003-NM-285-AD.

Applicability: Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 airplanes, serial number 003 through 585 inclusive; certificated in any category; with auxiliary power unit (APU) installation per Standard Option Only (S.O.O.) 8155 or Change Request (CR) 849SO08155.

Compliance: Required as indicated, unless accomplished previously.

To prevent a fuel leak caused by chafing of the APU fuel tube assembly, which could result in fire in the center wing area, accomplish the following:

Inspection, Relocation and Related Investigative and Corrective Actions

(a) Within 6 months after the effective date of this AD: Do a general visual inspection of the APU fuel tube assembly for discrepancies. The inspection includes examining the routing of the fuel tube assembly to ensure that the tube has sufficient clearance between the shroud of the bleed air duct and the gust lock cable; and inspecting the fuel tube assembly and the bleed air duct shroud for other discrepancies such as nicks, dents, chafing, or other damage. If the inspection shows no discrepancies, before further flight, relocate the clamps on the fuel tube assembly. If the inspection shows discrepancies, before further flight, do the applicable related investigative and corrective actions, and relocate the clamps on the fuel tube assembly. Accomplish all actions per the Accomplishment Instructions of Bombardier Service Bulletin 8-49-19, Revision A, dated July 7, 2003.

Note 1:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Inspections Accomplished Per Previous Issue of Service Bulletin

(b) Actions accomplished before the effective date of this AD per Bombardier Service Bulletin 8-49-19, dated May 13, 2003, are considered acceptable for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance

(c) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in Canada airworthiness directive CF-2003-22, dated September 3, 2003.

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Start Printed Page 28865

Issued in Renton, Washington, on May 11, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 04-11290 Filed 5-18-04; 8:45 am]

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